Mercury-IM/domain/src/main/java/org/mercury_im/messenger/core/viewmodel/chat/ChatViewModel.java

package org.mercury_im.messenger.core.viewmodel.chat;

import org.mercury_im.messenger.core.Messenger;
import org.mercury_im.messenger.core.SchedulersFacade;
import org.mercury_im.messenger.core.data.repository.Repositories;
import org.mercury_im.messenger.core.util.Optional;
import org.mercury_im.messenger.core.viewmodel.MercuryViewModel;
import org.mercury_im.messenger.entity.chat.DirectChat;
import org.mercury_im.messenger.entity.contact.Peer;
import org.mercury_im.messenger.entity.message.Message;

import java.util.List;

import io.reactivex.Observable;
import io.reactivex.subjects.BehaviorSubject;
import lombok.Getter;

public class ChatViewModel implements MercuryViewModel {

    private final Messenger messenger;
    private final Repositories repositories;
    private final SchedulersFacade schedulers;
    private DirectChat chat;

    @Getter
    private Observable<Peer> peer;

    @Getter
    private Observable<List<Message>> messages;

    @Getter
    private Observable<String> contactDisplayName;

    private final BehaviorSubject<Observable<List<Message>>> messageQueryObservable = BehaviorSubject.create();


    public ChatViewModel(Messenger messenger,
                         Repositories repositories,
                         SchedulersFacade schedulers) {
        this.messenger = messenger;
        this.repositories = repositories;
        this.schedulers = schedulers;
    }

    public void init(DirectChat directChat) {
        this.chat = directChat;
        //peer = repositories.getPeerRepository().observePeer(chat.getPeer());
        messageQueryObservable.onNext(repositories.getMessageRepository().observeMessages(chat));
        messages = Observable.switchOnNext(messageQueryObservable);

        peer = repositories.getPeerRepository().observePeer(chat.getPeer().getId())
                .filter(Optional::isPresent).map(Optional::getItem);

        contactDisplayName = repositories.getPeerRepository().observePeer(chat.getPeer())
                .map(optional -> optional.isPresent() ? optional.getItem().getDisplayName() : "DELETED");
    }

    public void onQueryTextChanged(String query) {
        if (query.trim().isEmpty()) {
            messageQueryObservable.onNext(repositories.getMessageRepository().observeMessages(chat));
        } else {
            messageQueryObservable.onNext(repositories.getMessageRepository().findMessagesWithBody(chat, query));
        }
    }
}